Method of treating veneers



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"UNITED STATES PATENT OFFICE.

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-This invention relates to av method of treating and laying veneers. In the manufacture of furniture of various types it is common to overlay an inner bed with a thin 'layerof a different and more expensive kind of wood than. that from which the bed is made. For instance, in the manufacture of a table top the bed may be of a relatively thick' and heavycheap wood while upon this bed a'veneer of much more expensive wood. may be laidand glued in place as well as atthe side and end edges thereof, the

veneer being of a wood capable of receiving a very high finish and one which will pre attractive appearance when fin- The veneers used are cut in very thin sheets and in many cases, particularly veneers known as crotch veneers (and the same is true of many othertypes' of so-called hard veneers) such veneers are liable to crack or fracture in handlin and particu larly after having been applied to the bed or stock which serves as a support therefor, due to the shrinking until after the article; of furniture to which the veneer has been a plied has been out in use for a considerab e known that checked and cracked veneers on articles of furniture are very-com1non, particularly in household ,It is a primary object and'purpose of the" present invention to provide a veneer and cracks pro furniture.

1 furniture having veneers produced accord-- ing to my method are accordingly insured against any future deterioration from this cause.

Inthe method of treating andla ing crotch" or other hard veneers which I ave devised, the thinsheets of veneer, singleply, which have-.been'cut in the usual way are first flattened and straightened, the same being sprayed or dampene with a dressing or sizing so as to moisten the same, the ve- Application filed April 0, 1925. Serial 10,21,212.

of the veneer with aconsequentformation of checks and cracks" therein This does not-occur many. times time but itis well -ing' the face grain of the under-pl same direction.

neers afterward bein panels or cauls to dry 1n the usual way, being allowed to. remain in this condition over night. The succeeding day the veneer sheets may be dried out between cauls which are. but slightly heated at first or lukewarm. The veneers have this process of drying repeated as many times as may be necessary with the cauls heated to big er degrees-of temperature until the same are dried so as to eliminate substantially all moisture coming from the application of the dressing or sizing thereto and are ready to be 'ointed in the usual wa if it is 11808588? or the size ofgthe bed to be covered. he jointing of pieces of veneer is'old and well known and need not beenem out and flatten tered into at this time other than to say that for any particular piece or pieces of work a sufficiently large sheet of veneer is made vby jointing together a plurality of pieces edge to edge to cover the particular piece or pieces of work desired.

hen the veneers have been properly jointed and otherwise work. for which it is designed each is glued to an under veneer referably of birch or maple. Slightl curl y maple veneer is preferred though-t is is not essential. The veneer first treated] is known as face veneer and this is lgluedto the under-pl of birch, maple-or .ot er desired veneer an in applgveneer to the under-py t e veneer should be parallel "to the grain in t e face veneer as much askpossible; also the joints of the face and un er veneers should not lie one over the other but should be separated some distance from each other, it being desirable to alwa 5 break the joints Thev thickness of the under veneer preferably is .one thirty second of an inch where birch or ma- .le' is used, though this may be subject to sight changes of dimensions so far as thickness is concerned. The underand face veneers are glued together in any suitable manner, vegetable glue being used as the same is not subject to crystalllzation rch fixed up to cover the where the joints are in t e and loss of binding power from heating as veneers made up each of an or maple preferably, and 1 become swollen and ex- I r regularllstock wi panded due to the moisture absorbed from the glue. The ordinary practice with veneers of this character is to dry the same out by air dr ing for a period of time, approximately asting for twenty-four hoursand then dry out further either once or twice in-heated cauls whereby nearly all of the moisture in the veneers is driven oil. This drying is not a rapid process as too rapid a dryin may resultin'causing blisters in the ue geriod of air drying followed by some artificial drying in cauls the temperature which will not at the highest likely exceed 125 de-. grees Fahrenheit, these veneers have hereto.- fqre been considered ready for laying on the work, that is, gluing to the-articles of furniture with which they are to be used.

With my process and method the veneers at this stage are further subjected to what I consider the essential and necessary step in order to make the same absolutely proof against any checking or cracking after the same have been laid on the work. This step consists in redrying the two-ply veneers taking them at the stage where heretofore they have been considered ready for laying on the work and placingthem in what is known as a veneer dryer. The two-ply veneers are placed between the plates of the veneer dryer, the plates closed and let stand for substan tially one minute or a little longer but not to exceed two minutes. The temperature of the plates in the veneer dryer may ran e anywhere between 230' to 300 degrees Fa 4 renheit but in practice I have found that 260 degrees Fahrenheit gives very satisfactory results. After the plates have been-closed for between one and two minutes and the two-ply veneer thus subjected to .r'edrying for that time the plates are" opened for a short period to permit any contraction of the two-ply veneer therein, then the plates again closed and let stand for approximately one more minute. The plates are then opened and the veneer taken therefrom, laid in a pile and weighted down so as to'keepthem as flat as possible. This completesthe operation of re'drying the veneers and unlessthe same are to laid on the work immediately. they must be kept in an absolutely dry lace until thei are wanted for. gluingv onto t e regular stoc therefor. j

As a result 'gree of tem rature notedall of thefmoisture is comp etelyiexpelled from the two-ply veneers and the same has shrunk to its minim and can .shrink no farther in this stateiwhe'n lued tothe under bed or glue 'ne between the veneers, but after a it is laid.

' dry face veneer and grees F said veneer to a point of the redryi-ng at'the'high de- .be 7 which it is used. the su thoroughly ,zand completely I two-ply veneer which is laid onthe can-j n'ot expand on-accountof moisture from the consists in gluing a plurahty as willnot the super-dried glue line between the face and under-ply veneer so as to reachthe face veneer and cause its expansion before the Y and under-ply of the two-ply veneer through a which the moisture does not penetrate. Ac-

cordingly there can be no further tendency for the veneers to ever further shrink or contract and thus develop checks'orcracks therein. There may be tendencies for the veneersto expand but this is counteracted and held against by the absolute tie made between the veneers and the-bed to which it is 80 glued and while there may be a potential force of expansion present in the veneers it is held against actively expanding while any drying out of the articles of furniture after they have reached the households where they are to be used cannot dry and contract the veneers below the point to whichthey were taken by the redrying of this method. No veneer subjected to the method described will thereafter develop any checks or cracks because of shrinking as it has had its greatest possible shrinkage before 1a ing in place v and is at its greatest state of s rinkage when a This invention while of simplecharacter has proved exceptionall practical in service and is now in use to a arge extent.

I claim: f r

1. The method of treating veneers which consists in luing together a commercially: dry face an backing veneer, drying the same, and then subjecting the same to a redrying o ration to thereby completely contract and shrink said veneers to a point beyond which they cannot further shrink,

substantially as described.

2. The method of treating veneers which consists in gluing together a commercially a commercially dry backing veneer, drying the same, and then subjecting the dried two-ply veneerto heat at a tern e ture between ahrenf heit to thereby drive off all. moisture andeompletelacontract and shrink ondwhich it canstantially as de-- not vfurther shrink, Bu scribed. I

3. The method of treating veneers which consists in two commercially dry. veneers toget er, then dryng the same, and then, subjecting the same to su rheat at a.

temperature exceeding the usual ighest tem 'perature for in to thereby drive'ofi'all moisture and yrnfi the veneers to ;a point ond hich they cannot further shrink,

tan tially as and for the purposes 'described. Z 4. The veneers which I p I of commercial-f ly dry sheets of veneer together, drying the method of eat ng 230and-300 dethen subjecting the same to a same in accordance with usual ractiee and g p a atioiratahigher degree of temperature to remove all moisture and shrink the veneers to a point beyond which they cannot fur-' ther shrink, substantially. as and for the purposes described.

5. The method of treating veneers which Consists in gluing two commercially single-ply veneer sheets together, drying the same after gluing in the usual manner, and then subjecting the same for short periods of time to a much higher degree of temperature to completely exclude all moisture and shrink said veneers to a point beyond which they cannot further shrink, substantiallyas ilescribed.

6. The method of treating veneers which consists in gluing together two sheets of commercially dry single-ply veneer, the same and then redrying the veneers by subjecting to a temperature between 230 and 300 degrees Fahrenheit for a. short period of time and then again subjecting them to said temperature for a second short period of time, substantially as described.

7. The method of treating veneers which consists in gluing together two sheets of commercially dry single-ply veneer, drying the same tlien clamping the same between heated plates heated to a temperature beclamping period to a point short period of time, not exceeding two minutes, then releasing the veneers from the plates and then again clamping the veneers between the plates and subjecting them to said heat for a. second short of timeapproximating one minute. 8. The method of treating veneers which dry consists in applying a glue size to two sheets of sin le-ply commercially dry veneer, drying' e same, gluingthe two sheets of veneers together, drying the veneer after gluing and then subjecting the ply veneer to high temperature same and eliminate all veneers, and

moisture from said completely shrinking the same shrink, substantially as described. I

9. The method oftreating veneers which consists in gluing together two thin sheets of commercially dry single-ply veneer, drying the same in accordance with usual practice and then subjecting the same to excess temperature and heat to redry the same and shrink the same to a point beyond which they cannot further shrink, substantially as described.

In testimony whereof l aflix my signature.

ALFRED A. DENNIS.

and heat to redry the yond which it cannot further 

